The proposal deals with membrane permeability and cellular compartmentation as controlling elements in the physiology of intact plant organs such as fruits and tubers, in tissue slices therefrom, and in cellular organelles. We plan to further investigate our observations that glycolysis and tricarboxylic acid cycle activity are controlled at least in part by the separation within the cell of key regulatory enzymes from their positive modulators, including both selected cations and substrate molecules. We have ripened fruits with low levels of gaseous cyanide and carbon monoxide with attendent respiratory stimulation rather than inhibition. Stimulation of phosphofructokinase (PFK) activity and phosphoenolypyruvate kinase (PK) activity have been implicated in the response, as has stimulation of isocitrate dehydrogenase. We will experimentally test the thesis that besides ethylene, compounds which are effective in ripening fruit, and enhancing tuber respiration, do so by increasing intracellular membrane permeability. While carbohydrate oxidation characterizes tuber respiration and the respiration of aged tissue slices, fresh slice respiration predominantly comprises lipid catabolism -- specifically the gamma-oxidation of long chain fatty acids. We have reason to believe the lipid arises from degraded membranes. Our investigation will deal with the genesis of the very active lipase and lipoxygenase activity which attends slicing, and the particular question of whether these enzymes are released from spherosomes or are latent in the several types of cell membranes. The locus of the fatty acid gamma-oxidase system will be investigated as will its possible link to conventional electron transport system through NADH. A third facet of the program will deal with mitochondrial membrane characteristics as related to the enhancement of State 3 oxidation rates ("conditioning") with alternating State 3/State 4 experiences. We wish to elucidate the basis for the increasing response to uncouplers, to the diminishing Arrhenius activation energy for substrate oxidation by membrane-bound enzymes, and to the conversion from cooperative to noncooperative kinetics on the part of mitochondrial isocitrate dehydrogenase, all of which attend the conditioning process.